String base64;
		
		base64 = request.getParameter("picture").replace(" ", "+");
		System.out.println(base64);
		//Base64解碼
		Base64.Decoder decoder = Base64.getDecoder();
		byte[] picture = decoder.decode(base64);

		//解碼後的二進位制資料寫入檔案
		BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream("/home/hao/圖片/test1.jpg"));
		out.write(picture, 0, picture.length);
		out.close();
 

使用上面的程式碼可以將base64的字串轉為圖片儲存，注意：“+”號通過spring的controller會被轉義為空格“ ”